Background
[0001] The present invention relates to a transmitter for predicting stress on a formwork
element. Furthermore, the present invention relates to a system for predicting stress
on a formwork element. In addition, the present invention relates to a formwork element
for use in a formwork.
[0002] Furthermore, the present invention relates to a method for transmitting data for
predicting stress on a formwork element.
[0003] In addition, the present invention relates to a method for predicting stress on a
formwork element.
[0004] When pouring a building material into a formwork structure comprising a plurality
of formwork elements interconnected to each other, an important aspect is to monitor
stress on said formwork elements that is induced into the formwork elements by the
building material.
[0005] When casting concrete there is a risk that the concrete form is subjected to loads
it cannot handle. This can lead to formwork failure. The concrete formwork geometry
could change leading to a flawed end product, for example curved walls or in the worst
case scenario, an ultimate collapse of the entire formwork structure.
[0006] An uneven load distribution within the formwork structure could also lead to local
failures or an unwanted redistribution of loads. One or more tie rods taking up more
load than expected can lead to instant tie rod failure.
[0007] Without knowing the strain or loads the formwork is subjected to, one has to fill
the formwork very slowly or divide the pour into multiple stages, letting the concrete
harden or at least solidify between each stage.
[0008] Dividing the pour into multiple stages often leads to visible joints, so-called cold
joints, or variations of surface color and structure creating an end product of lesser
quality.
[0009] Pouring speed and time is not only a factor affecting the physical end result, it
is also very closely tied to the economical success of the operation. Hence, it is
of interest to the contractor to fill the formwork and do the pour as quick and effective
as possible while not jeopardizing the end result or the form place safety.
[0010] KR 20090016780 discloses a mold deformation detecting apparatus which is configured to detect deformation
of a mold which supports a load when concrete is put into the mold and warn of danger
so as to prevent safety accidents. A mold deformation detecting apparatus includes
a detector and a controller. The detector detects a motion of a mold. The controller
receives a signal from the detector and checks whether the mold is deformed. The frontend
of the detector has a sensing bar in close proximity to the mold. The apparatus detects
mold deformation according to whether the sensing bar is rotated.
[0011] KR 20130070874 discloses a mold collapse sign detecting device comprising a clamp, a sensor, an
A/D converter, a microcontroller, and a warning unit. The state in which the clamp
is interlocked to a mold frame is detected by the sensor. Detected data is outputted
from the sensor in a predetermined time after detecting the interlocking of the clamp
and is memorized as a standard value. Change value applied to the mold frame is calculated
by periodically comparing the detected data and the standard value. When the change
value exceeds a critical value, a warning signal is outputted.
[0012] Consequently, there is a need to further improve systems and methods for predicting
stress on a formwork element during and/or after pouring a building material into
a space enclosed by a formwork.
Disclosure of the invention
[0013] The present invention relates to a transmitter for predicting stress on a formwork
element during and/or after pouring a building material, in particular concrete, into
a space enclosed by a formwork in accordance with claim 1, to a system for predicting
stress on a formwork element during and/or after pouring a building material, in particular
concrete, into a space enclosed by the framework in accordance with claim 2, to a
formwork element for use in a formwork in accordance with claim 7, to a method for
transmitting data for predicting stress on a formwork element during and/or after
pouring a building material, in particular concrete, into a space enclosed by the
formwork in accordance with claim 15 and to a method for predicting stress on a formwork
element in accordance with claim 16.
[0014] Further embodiments of the present invention are subject of the further sub-claims
and of the following description, referring to the drawings.
[0015] An aspect of the present invention relates to a transmitter for predicting stress
on a formwork element during and/or after pouring a building material, in particular
concrete, into a space enclosed by a formwork including the formwork element, the
formwork element comprising a form face and a support structure which is attached
to the form face and supporting the form face, wherein the form face is separated
from or integrated into the support structure.
[0016] The transmitter comprises the formwork element and data acquisition means comprising
at least one sensor unit configured to acquire data in relation to the stress exerted
on the formwork element by the building material, a control unit configured to control
the at least one sensor unit and/or to process the acquired data, and a transmission
unit configured to transmit the acquired data to a device located outside the formwork
element, wherein the control unit and the transmission unit are arranged within the
support structure, and wherein the at least one sensor unit is arranged at least partially
within the support structure.
[0017] A further aspect of the present invention relates to a system for predicting stress
on a formwork element during and/or after pouring a building material, in particular
concrete, into a space enclosed by a formwork including the formwork element, comprising
the transmitter and the device configured to receive the acquired data.
[0018] A further aspect of the present invention relates to a formwork element for use in
a formwork, comprising a form face and a support structure which is attached to the
form face and supporting the form face, wherein the form face is separated from or
integrated into the support structure, the formwork element comprising data acquisition
means comprising at least one sensor unit configured to acquire data in relation to
the stress exerted on the formwork element by the building material, a control unit
configured to control the at least one sensor unit and/or to process the acquired
data, and a transmission unit configured to transmit the acquired data to a device
located outside the formwork element, wherein the control unit and the transmission
unit are arranged within the support structure, and wherein the at least one sensor
unit is arranged at least partially within the support structure.
[0019] A further aspect of the present invention relates to a method for transmitting data
for predicting stress on a formwork element during and/or after pouring a building
material, in particular concrete, into a space enclosed by a formwork including the
formwork element, the formwork element comprising a form face and a support structure
which is attached to the form face and supporting the form face.
[0020] The form face is separated from or integrated into the support structure, the method
comprising the steps of acquiring data in relation to the stress exerted on the formwork
element by the building material by means of at least one sensor unit of a data acquisition
means, controlling the at least one sensor unit by means of a control unit and/or
processing the acquired data, wherein the control unit and the transmission unit are
arranged within the support structure.
[0021] The at least one sensor unit is arranged at least partially within the support structure,
and transmitting the acquired data to a device located outside the formwork element
by a transmission unit.
[0022] A further aspect of the present invention relates to a method for predicting stress
on a formwork element during and/or after pouring a building material, in particular
concrete, into a space enclosed by a formwork including the formwork element, the
method comprising the method for transmitting data for predicting stress on a formwork
element according to the invention, and further comprising receiving the acquired
data by means of the device.
[0023] The idea of the present invention is to acquire the relevant data by the data acquisition
means, process the data and transmit it to a device located outside the formwork element
such that a user receives live data on the stress exerted on the formwork elements
by the building material being poured into the formwork thus enabling the user to
adjust e.g. a pouring speed and other relevant parameters.
[0024] Due to the fact that the system comprises the transmitter, the control unit and the
device, a plurality of datasets can be taken into account when analyzing the pour
of the building material into the formwork such as known data about the formwork,
currently obtained data of the ongoing pour and data on all earlier pours that the
system has monitored.
[0025] The properties of standardized formwork parts are well-known to any supplier of such
equipment. The properties can be easily described and do not change due to the normal
temperature changes, time or any other external factor during normal use. The properties
of the formwork form face, the distances between e.g. tie rods and other fasteners
in any given section of the formwork are known as well as the dimensions such as height,
width, and depth of the formwork construction as a whole.
[0026] The formwork can thus be said to be a system of very well-standardized parts put
together in a very well-described way forming a known unit.
[0027] The invention thus uses the concrete form, i.e. the formwork elements, as an integrated
monitoring system where the formwork elements themselves act as parts of the sensing
mechanism measuring the effect of the fresh concrete pressure on the formwork elements.
Information about the formwork elements respective position in the total formwork
construction is also used for the analysis.
[0028] According to an embodiment, the device is configured to analyze the data received
from the data acquisition means and to display an analysis result to a user via a
graphical user interface, and wherein the device is further configured to provide
instructions to the user for handling a pouring process.
[0029] The user is thus provided with a simple and easy to use graphical user interface
indicating all relevant parameters of the ongoing pour that is capable of providing
instructions to the user for making appropriate adjustments.
[0030] According to a further embodiment, the transmission unit is configured to continuously
transmit data to the device in duplex communication, and wherein the data is transferrable
by cable or wirelessly. Due to the fact that the data is continuously transmitted
to the device, accurate and on-time data can be obtained that in turn gives the user
an accurate representation of a status of the ongoing pour, in particular with a view
to the stress exerted by the building material on the formwork elements.
[0031] According to a further embodiment, the device is configured to perform an analysis
of the stress on the formwork element during and/or after pouring the building material
using the data received from the data acquisition means, and data of previous building
material pours monitored by the system. The system is thus capable of continuously
monitoring the stress exerted by the building material on the formwork elements, i.e.
during and/or after the pour, as the stress varies during different points in time
during and after the pour.
[0032] According to a further embodiment, the system further comprises a data storage unit
configured to store the acquired data, and a data interface configured to connect
to a further system, in particular a CAD-system for designing formwork structures.
The data obtained during and/or after the pour can thus advantageously be used by
the CAD-system when designing objects, e.g. buildings and/or formwork structures.
[0033] According to a further embodiment, the at least one sensor unit extends through an
opening formed in the support structure, the sensor unit comprising a pressure transducer
holding body, a pressure chamber, a pressure sensor, in particular a pressure transducer,
arranged at least partially within the pressure transducer holding body and inserted
at least partially into or being arranged adjacent to the pressure chamber at a first
axial end portion of the pressure chamber and a membrane covering an opening of the
pressure chamber at a second axial end portion of the pressure chamber.
[0034] The pressure chamber contains a hydraulic fluid and is configured to contact the
building material and to perform continuous measurement of lateral pressure on the
form face of the formwork element. Said pressure sensor, in particular the pressure
transducer, is thus capable of measuring the concrete pressure at well-defined points
by being integrated in the formwork parts, wherein the sensor membrane is in contact
with the concrete.
[0035] According to a further embodiment, the pressure chamber is axially adjustable in
position through an opening formed in a base plate of the sensor unit, wherein the
sensor unit comprises fixing means configured to lock and unlock the pressure chamber
relative to the base plate. The adjustability of the pressure chamber and thus of
the sensor unit relative to the formwork element thus enables to use only one sensor
unit no matter the thickness of the formwork element, in particular the thickness
of a plywood plate that forms a form face in contact with the building material.
[0036] According to a further embodiment, the at least one sensor unit is formed by a deflection
sensor configured to perform continuous measurement of a deflection of the form face
of the formwork element. By being able to measure the deflection of the formwork element
by means of the sensor being integrated into the formwork element, an accurate indication
of the stress exerted by the building material on the formwork elements can be obtained.
[0037] According to a further embodiment, the deflection sensor comprises a push rod extending
through an opening formed in the support structure adjacent to the form face of the
formwork element, the push rod abutting the form face, wherein the push rod is pre-loaded
against the form face by a first spring element. The deflection sensor can thus measure
any changes in the position of the form face in relation to a support structure of
the formwork element.
[0038] According to a further embodiment, the deflection sensor further comprises a magnet
lever connected to the push rod at a first end portion of the magnet lever, wherein
the magnet lever at its second end portion comprises a first permanent magnet and
a second permanent magnet, wherein a hall effect sensor is arranged between the first
permanent magnet and the second permanent magnet of the magnet lever, wherein the
magnet lever is adapted to move upon movement of the push rod, and wherein the hall
effect sensor is configured to detect a movement of the magnet lever. By using the
hall effect sensor, an accurate measurement of any movement of the lever caused by
a movement of the form face of the formwork element can be obtained.
[0039] According to a further development, the at least one sensor unit is formed by a strain
gauge configured to measure a load on a tie rod arranged between the formwork element
and an adjacent formwork element using compression strain gauge load cells integrated
in a tie rod assembly. Thus, an accurate measurement of the load on the tie rod can
be performed.
[0040] According to a further development, the at least one sensor unit is formed by a temperature
sensor configured to measure a temperature of the building material, wherein the temperature
sensor forms contact with the building material or is integrated in the pressure sensor
unit, and/or a sound sensor is configured to detect formwork movements using an electrostatic
capacitor-based microphone attached to the form face.
[0041] Therefore, advantageously additional data can be obtained by using the temperature
sensor and/or the sound sensor that is usable in the overall analysis of the stress
exerted on the formwork elements by the building material. In addition, information
on loss of workability and hardening of the concrete can advantageously be obtained
by means of the temperature sensor and by recording the sound.
[0042] According to a further embodiment, the method for predicting stress on a formwork
element further comprises the step of measuring the stress exerted on the formwork
at various positions in the formwork by means of a plurality of sensor units. In doing
so, a more accurate measurement of various positions across the entire surface of
the form phase of the formwork element can be obtained.
[0043] According to a further embodiment, the device is configured to perform an analysis
of the stress on the formwork element during and/or after pouring the building material
using the data received from the data acquisition means and data of previous building
material pours monitored by the system.
[0044] The data obtained during and/or after the pour can thus advantageously be used by
the CAD-system when designing objects, e.g. buildings and/or formwork structures.
[0045] The herein described features of the transmitter for predicting stress on a formwork
element, the system for predicting stress on a formwork element, the formwork element
itself are also disclosed in the method for transmitting data for predicting stress
on a formwork element and in the method for predicting stress on a formwork element.
Brief description of the figures
[0046] For a more complete understanding of the present invention and advantages thereof,
reference is now made to the following description taken in conjunction with the accompanying
drawings. The invention is explained in more detail below using exemplary embodiments,
which are specified in the schematic figures of the drawings, in which:
- Fig. 1
- shows a schematic view of a system for predicting stress on a formwork element according
to a preferred embodiment of the invention;
- Fig. 2
- shows a cross-sectional view of the formwork element comprising a transmitter and
a perspective view of external devices according to the preferred embodiment of the
invention;
- Fig. 3
- shows a cross-sectional view of a sensor unit according to the preferred embodiment
of the invention;
- Fig. 4
- shows an exploded view of a further sensor unit according to the preferred embodiment
of the invention;
- Fig. 5
- shows components of the further sensor unit according to the preferred embodiment
of the invention;
- Fig. 6
- shows a schematic view of the formwork element comprising the further sensor unit
according to the preferred embodiment of the invention;
- Fig. 7
- shows a schematic view of an inside of the formwork element comprising the further
sensor unit according to the preferred embodiment of the invention;
- Fig. 8
- shows a cross-sectional view of the formwork element comprising the further sensor
unit;
- Fig. 9
- shows a cross-sectional view of a further sensor unit according to the preferred embodiment
of the invention;
- Fig. 10
- shows a schematic view of the further sensor unit depicted in Fig. 9 in a first position
according to the preferred embodiment of the invention;
- Fig. 11
- shows a schematic view of the further sensor unit depicted in Fig. 9 in a second position
according to the preferred embodiment of the invention; and
- Fig. 12
- shows a flow diagram of a method for predicting stress on the formwork element according
to the preferred embodiment of the invention.
[0047] Unless indicated otherwise, like reference numerals or signs to the figures indicate
like elements.
Detailed description of the embodiments
[0048] Fig. 1 shows a schematic view of a system for predicting stress on a formwork element
according to a preferred embodiment of the invention.
[0049] The system 1 for predicting stress on a formwork element 10 during and/or after pouring
a building material, in particular concrete, into a space enclosed by the formwork
2 is depicted in Fig. 1. The formwork 2 comprises a plurality of interconnected formwork
elements 10, each formwork element 10 comprising a form face 12 and a support structure
14 supporting the form face 12.
[0050] Fig. 2 shows a cross-sectional view of the formwork element comprising a transmitter
and a perspective view of external devices according to the preferred embodiment of
the invention.
[0051] In Fig. 2, building material M, in particular concrete, is poured into the space
enclosed by the formwork 2 by means of the pouring device 3. The depicted formwork
element 10 comprises the form face 12 and the support structure 14 attached to the
form face and supporting the form face, wherein the form face is separated from the
support structure. Alternatively, the form face may be integrated into the support
structure 14.
[0052] The system 1 comprises data acquisition means 16a, 16b, 16c, 16d, 16e. The data acquisition
means 16a, 16b, 16c, 16d, 16e comprises at least one sensor unit. In the present embodiment,
it comprises a plurality of sensor units 18a, 18b, 18c, 18d, 18e that are each configured
to acquire data in relation to the stress exerted on the formwork element 10 by the
building material M.
[0053] The temperature sensor 18d and/or sound sensor 18e can be integrated into the one
or more of the other sensors 18a, 18b, 18c.
[0054] The system 1 further comprises a control unit configured to control the sensor unit.
In the present embodiment, there are a plurality of control units, each control unit
configured to control a dedicated sensor unit. The control unit 20a, 20b, 20c, 20d,
20e also processes the acquired data. Alternatively, the control unit 20a, 20b, 20c,
20d, 20e may either be configured to control the sensor unit 18a, 18b, 18c, 18d, 18e
or process the acquired data.
[0055] The system 1 further comprises a transmission unit 22a, 22b, 22c, 22d, 22e that is
configured to transmit the acquired data to a device 24 located outside the formwork
element 10. The control unit 20a, 20b, 20c, 20d, 20e and the transmission unit 22a,
22b, 22c, 22d, 22e are arranged within the support structure 14.
[0056] Each sensor unit 18a, 18b, 18c, 18d, 18e is arranged partially within the support
structure 14. Alternatively, the sensor unit may be fully embedded into the support
structure 14.
[0057] Moreover, each sensor unit 18a, 18b, 18c, 18d, 18e is formed by a strain gauge 18c
configured to measure a load L on a tie rod 52 arranged between the formwork element
10 and an adjacent formwork element 11 using compression strain gauge load cells 54
integrated in a tie rod assembly 56. Alternatively, the compression strain gauge load
cells 54 can be arranged in the formwork element where the tie rod 52 is inserted.
[0058] A temperature sensor 18d is configured to measure a temperature of the building material
M, wherein the temperature sensor 18d forms contact with the building material M.
[0059] Alternatively, the temperature sensor can be integrated in the pressure sensor unit
18a, and/or a sound sensor 18e configured to detect formwork 2 movements using an
electrostatic capacitor-based microphone attached to the form face 12.
The speed of the chemical reactions in the concrete is directly related to the temperature.
The sound can be used to determine when the casting started, possibly the location
of the concrete surface and the amount of vibration added. Dangerous relocation of
the formwork could possibly also be detected.
[0060] The device 24 is configured to analyze the data received from each of the data acquisition
means 16a, 16b, 16c, 16d, 16e and to display an analysis result to a user via a graphical
user interface 26. The device 24 may alternatively forward the received data to a
server (not shown on Fig. 2) via an internet connection, wherein the server performs
the data analysis and provides an analysis result to the device.
[0061] The relevant data is acquired by the data acquisition means 16a, processed and transmitted
to the device 24 located outside the formwork element 10 such that a user receives
live data on the stress exerted on the formwork element 10 by the building material
being poured into the formwork thus enabling the user to adjust e.g. a pouring speed
and other relevant parameters.
[0062] In addition, e.g. a warning function can be implemented by the device 24 or a further
device (not shown in Fig. 2) that may warn the user of immediate danger should this
be indicated by the data analysis of the stress exerted on the formwork element 10.
Said warning may be issued visually and/or acoustically on the device 24 and/or another
device (not shown in Fig. 3) such as a warning light and/or a siren located on the
construction site.
[0063] The device 24 is further configured to provide instructions to the user for handling
a pouring process. Each transmission unit 22a, 22b, 22c, 22d, 22e is configured to
continuously transmit data to the device 24 in duplex communication. The data is transferred
wirelessly. Alternatively, the data may be transferred by cable.
[0064] The device 24 is configured to perform an analysis of the stress on the formwork
element 10 during and after pouring the building material M using the data received
from each of the data acquisition means 16a, 16b, 16c, 16d, 16e and data of previous
building material pours monitored by the system. Alternatively, said analysis may
be performed by other components (not shown) connected to the device.
[0065] Alternatively, the device 24 may be configured to perform the analysis of the stress
on the formwork element 10 either during or after pouring the building material.
[0066] The system 1 further comprises a data storage unit 28 that is configured to store
the acquired data and a data interface 30 configured to connect to a further system
32, in particular a CAD-system for designing formwork structures. The data storage
unit 28 is located at the construction site. Alternatively, the data storage unit
28 may be embodied as a web-server connected to the device by an internet connection.
[0067] Fig. 3 shows a cross-sectional view of a sensor unit according to the preferred embodiment
of the invention.
[0068] The sensor unit 18b is formed by a deflection sensor configured to perform continuous
measurement of a deflection of the form face 12 of the formwork element 10. Moreover,
the sensor unit 18b is also configured to measure an oscillation or vibration of the
form face 12 of the formwork element 10. This way, information on a vibration and
compaction of the concrete can advantageously obtained.
[0069] The form face 12 of the formwork element 10 in this configuration acts as a membrane
thus enabling measurement over a significantly larger area than is conventionally
the case with pressure sensors.
[0070] The deflection sensor 18b comprises a push rod 38 extending through an opening formed
in the support structure 14 adjacent to the form face 12 of the formwork element 10.
[0071] The push rod 38 abuts the form face 12, wherein the push rod 38 is pre-loaded against
the form face 12 by a first spring element 42.
[0072] The deflection sensor 18b further comprises a magnet lever 44 connected to the push
rod 38 at a first end portion 44a of the magnet lever 44.
[0073] The magnet lever 44 and its second end portion 44b comprises a first permanent magnet
46 and a second permanent magnet 48.
[0074] A hall effect sensor 50 is arranged between the first permanent magnet 46 and the
second permanent magnet 48 of the magnet lever 44, wherein the magnet lever 44 is
adapted to move upon movement of the push rod 38. The hall effect sensor 50 is configured
to detect a movement of the magnet lever 44.
[0075] The movements detected by the hall effect sensor 50 can e.g. be movements where the
form face 12 returns to its original position after the movement or quick oscillations,
i.e. vibrations of the form face 12. This is important information for the concrete
worker since he can get information on how much the concrete has been vibrated. Vibration
of concrete is an integral part of the casting procedure.
[0076] Moreover, the magnet lever comprises a slit that is substantially arc-shaped, in
which a rod is inserted, that is held by an arm 80 that is preferably fork-shaped,
i.e. U-shaped, in order to be able to hold the rod between respective end portions.
[0077] The arm 80 is further held in place by a spring against which an amplification set
screw 84 is pushed that extends through the support structure 14 of the formwork element
10.
[0078] The sensor unit 18b further comprises a square nut which follows adjustments of a
pre-load screw 86 that extends through the support structure of the formwork element
and pre-loads the first spring element 42.
[0079] The preload set screw 86 also conveys the rotary motion to the screw (not numbered)
that is in contact with the push rod 38. This has the effect that the preload does
not create an offset on the magnet lever 44 since it is fastened to the screw with
square nuts having the exact same thread pitch as the preload screw. Preloading the
push rod 38 with the preload set screw 86 thus does not change the position of the
magnet lever 44.
[0080] Fig. 4 shows an exploded view of a further sensor unit according to the preferred
embodiment of the invention.
[0081] The sensor unit 18a comprises a pressure transducer holding body 66, a pressure chamber
60, a pressure transducer 67, in particular a pressure transducer, arranged partially
within the pressure transducer holding body 66 and inserted partially into the pressure
chamber 60 at a first axial end portion of the pressure chamber 60.
[0082] The sensor unit 18a further comprises a membrane 63 covering an opening of the pressure
chamber 60 at a second axial end portion of the pressure chamber 60, wherein the pressure
chamber 60 contains a hydraulic fluid (not shown in Fig. 4) and is configured to contact
the building material and to perform continuous measurement of lateral pressure on
the form face of the formwork element.
[0083] The pressure transducer holding body 66 further comprises an opening 65 formed at
a front face of the pressure transducer holding body. The sensor unit 18a moreover
comprises a flange 58, wherein in an assembled state of the sensor unit 18a, the flange
58 is screwed to a container portion 64 of the sensor unit 18a that comprises the
pressure chamber 60, wherein the membrane 63 is arranged between the flange 58 and
the container portion 64. The opening 65 in the pressure transducer holding body 66
serves such that a screw can be inserted from a given direction in order to fix the
container portion 64 to the pressure transducer holding body 66.
[0084] This is a very light press-fit. Pressure is then applied to compress the o-ring in
an o-ring groove 62 using the screws mentioned in the comment above.
[0085] The pressure transducer holding body 66 pushes against the container portion 64 by
the means of two screws through holes marked with arrows in Fig 4. These screws in
effect compresses an o-ring in the o-ring groove 62 in Fig 4. The o-ring creates a
water tight seal against the form work element body 14. This solves the problem of
how to fasten the sensor assembly without having fasteners subjected to fresh concrete.
All assembly and disassembly can be made from the outside of the formwork.
[0086] Fig. 5 shows components of the further sensor unit according to the preferred embodiment
of the invention.
[0087] The sensor unit 18a comprises a base plate in which an opening 70 is formed through
which the sensor can be inserted. The sensor unit 18a furthermore comprises the control
unit 20a and the transmission unit 22a, which in the present embodiments are housed
within a common housing. The sensor unit 18a further comprises mounting means 68a,
68b, 68c, 68d that are adapted to receive screws that may be screwed into said mounting
means through a wall of the formwork element (not shown in Fig. 5).
[0088] Fig. 6 shows a schematic view of the formwork element comprising the further sensor
unit according to the preferred embodiment of the invention.
[0089] The formwork element 10 comprises the support structure 14. In the present embodiment,
the support structure is formed by a beam made of a metal material, in particular
aluminum, wherein the sensor unit 18a is inserted through an opening of the support
structure. The sensor unit 18a comprises at an outer surface additionally a USB-connector
74, a status indicating light 78 and a button 76.
[0090] The button has multiple functions. The button is used to turn the unit on or off,
and reset. It can also be used to "force connect". That is to create a measurement
and connect immediately to the main unit as the button is pushed so as not to wait
for the next scheduled measurement.
[0091] Alternatively, other buttons having other functions may be placed on the outside
of the sensor unit 18a.
Fig. 7 shows a schematic view of an inside of the formwork element comprising the
further sensor unit according to the preferred embodiment of the invention.
[0092] The sensor unit 18a is arranged at an inside of the support structure, said support
structure 14 being made of a profile element that is substantially hollow and has
a rectangular cross-section. The control unit 20a and the transmission unit 22a are
shown which are connected to the USB-connector on the outside of the support structure
by means of a cable.
[0093] Fig. 8 shows a cross-sectional view of the formwork element comprising the further
sensor unit.
[0094] The sensor unit 18a is shown in assembled state in which it is connected to the control
unit 20a and the transmission unit 22a, wherein a membrane 36 extends through an opening
34 of the support structure 14. Thus, building material M that is being poured into
the space enclosed by respective formwork elements exerts a substantially lateral
pressure on said membrane 36 of the sensor unit 18a.
[0095] Fig. 9 shows a cross-sectional view of a further sensor unit according to the preferred
embodiment of the invention. Fig. 9 is a modified version of the pressure sensor 18a
depicted in Fig. 4. In the present embodiment, the pressure sensor comprises a pressure
chamber 60 that is axially adjustable in position through an opening formed in a base
plate 61 of the sensor unit 18a, wherein the sensor unit 18a comprises fixing means
61a configured to lock and unlock the pressure chamber 60 relative to the base plate
61. Moreover, the form face 12 consists of two layers that are arranged back-to-back,
said form face being made of a plywood plate. Alternatively the form face 12 may for
example be made of steel or plastic.
[0096] The pressure chamber 60a is formed as a fluid filled cavity. Air vent screw 60b communicates
with the pressure chamber 60a and is adapted to bleed the pressure chamber 60a.
[0097] The pressure transducer 67 measures a pressure of the fluid disposed in the pressure
chamber 60a.
[0098] Fig. 10 shows a schematic view of the further sensor unit depicted in Fig. 9 in a
first position according to the preferred embodiment of the invention. In the present
view, the pressure chamber is shown in a first position, in which it is substantially
retracted.
[0099] Fig. 11 shows a schematic view of the further sensor unit depicted in Fig. 9 in a
second position according to the preferred embodiment of the invention.
[0100] The pressure chamber 60 in the present depiction is substantially fully extended.
This enables the sensor unit 18a to be also used with thicker formwork elements without
having to replace the sensor unit 18a with another sensor unit having longer dimensions.
[0101] Fig. 12 shows a flow diagram of a method for predicting stress on the formwork element
according to the preferred embodiment of the invention.
[0102] The method comprises the steps of acquiring S1 data in relation to the stress exerted
on the formwork element 10 by the building material M by means of at least one sensor
unit 18a, 18b, 18c, 18d, 18e of a data acquisition means 16a, 16b, 16c, 16d, 16e.
[0103] The method moreover comprises the step of controlling S2 the at least one sensor
unit 18a, 18b, 18c, 18d, 18e by means of a control unit 20a, 20b, 20c, 20d, 20e and/or
processing the acquired data S2', wherein the control unit 20a, 20b, 20c, 20d, 20e
and the transmission unit 22a, 22b, 22c, 22d, 22e are arranged within the support
structure 14, and the at least one sensor unit 18a, 18b, 18c, 18d, 18e is arranged
at least partially within the support structure 14.
[0104] The method further comprises the step of transmitting S3 the acquired data to the
device 24 located outside the formwork element 10 by the transmission unit 22a, 22b,
22c, 22d, 22e.
[0105] The method further comprises the step of S4 receiving the acquired data by means
of the device 24.
[0106] Although the afore-mentioned system has been described in connection with formwork
elements of a formwork structure, a person skilled in the art is aware of the fact
that the herein described system can of course be applied to other structures in which
a stress of a medium against a containing structure is to be monitored.
[0107] Although specific embodiments have been illustrated and described herein, it will
be appreciated by those of ordinary skill in the art that a variety of alternate and/or
equivalent implementations exist. It should be appreciated that the exemplary embodiment
or exemplary embodiments are only examples, and are not intended to limit the scope,
applicability, or configuration in any way.
[0108] Rather, the foregoing summary and detailed description will provide those skilled
in the art with a convenient road map for implementing at least one exemplary embodiment,
it being understood that various changes may be made in the function and arrangement
of elements described in an exemplary embodiment without departing from the scope
as set forth in the appended claims and their legal equivalents.
[0109] Generally, this application is intended to cover any adaptations or variations of
the specific embodiments discussed herein.
Reference List
[0110]
- 1
- system
- 2
- formwork
- 3
- pouring device
- 10
- formwork element
- 12
- form face
- 14
- support structure
- 16a, 16b, 16c, 16d, 16e
- data acquisition means
- 18a, 18b, 18c, 18d, 18e
- sensor unit
- 20a, 20b, 20c, 20d, 20e
- control unit
- 22a, 22b, 22c, 22d, 22e
- transmission unit
- 24
- device
- 26
- graphical user interface
- 28
- storage unit
- 30
- data interface
- 32
- further system
- 34
- opening
- 36
- membrane
- 38
- push rod
- 40
- opening
- 44
- magnet lever
- 44a
- first end portion
- 44b
- second end portion
- 46
- first permanent magnet
- 48
- second permanent magnet
- 50
- hall effect sensor
- 52
- tie rod
- 54
- compression strain gauge load cells
- 56
- tie rod assembly
- 58
- flange
- 60, 60a
- pressure chamber
- 60b
- air vent screw
- 61
- base plate
- 61a
- fixing means
- 62
- o-ring groove
- 63
- membrane
- 64
- containing portion
- 65
- opening
- 66
- pressure transducer holding body
- 67
- pressure transducer
- 68a, 68b, 68c, 68d
- mounting means
- 70
- opening
- 74
- connector
- 76
- button
- 78
- status indicating light
- 80
- arm
- 84
- amplification set screw
- 86
- pre-load screw
- M
- building material
- P
- lateral pressure
1. Transmitter for predicting stress on a formwork element (10) during and/or after pouring
a building material (M), in particular concrete, into a space enclosed by a formwork
(2) including the formwork element (10), the formwork element (10) comprising a form
face (12) and a support structure (14) which is attached to the form face (12) and
supporting the form face (12), wherein the form face (12) is separated from or integrated
into the support structure (14), the transmitter comprising:
the formwork element (10); and
data acquisition means (16a, 16b, 16c, 16d, 16e) comprising at least one sensor unit
(18a, 18b, 18c, 18d, 18e) configured to acquire data in relation to the stress exerted
on the formwork element (10) by the building material (M), a control unit (20a, 20b,
20c, 20d, 20e) configured to control the at least one sensor unit (18a, 18b, 18c,
18d, 18e) and/or to process the acquired data, and a transmission unit (22a, 22b,
22c, 22d, 22e) configured to transmit the acquired data to a device (24) located outside
the formwork element (10), wherein the control unit (20a, 20b, 20c, 20d, 20e) and
the transmission unit (22a, 22b, 22c, 22d, 22e) are arranged within the support structure
(14), and wherein the at least one sensor unit (18a, 18b, 18c, 18d, 18e) is arranged
at least partially within the support structure (14) .
2. System (1) for predicting stress on a formwork element (10) during and/or after pouring
a building material (M), in particular concrete, into a space enclosed by a formwork
(2) including the formwork element (10), comprising the transmitter of claim 1 and
the device (24) configured to receive the acquired data.
3. The system of claim 2, wherein the device (24) is configured to analyze the data received
from the data acquisition means (16a, 16b, 16c, 16d, 16e) and to display an analysis
result to a user via a graphical user interface (26), and wherein the device (24)
is further configured to provide instructions to the user for handling a pouring process.
4. The system of claim 2 or 3, wherein the transmission unit (22a, 22b, 22c, 22d, 22e)
is configured to continuously transmit data to the device (24) in duplex communication,
and wherein the data is transferable by cable or wirelessly.
5. The system of claim 3 or 4, wherein the device (24) is configured to perform an analysis
of the stress on the formwork element (10) during and/or after pouring the building
material (M) using the data received from the data acquisition means (16a, 16b, 16c,
16d, 16e) and data of previous building material (M) pours monitored by the system.
6. The system of any one of claims 2 to 5, further comprising a data storage unit (28)
configured to store the acquired data, and a data interface (30) configured to connect
to a further system (32), in particular a CAD-system for designing formwork structures.
7. Formwork element (10) for use in a formwork (2), comprising a form face (12) and a
support structure (14) which is attached to the form face (12) and supporting the
form face (12), wherein the form face (12) is separated from or integrated into the
support structure (14), the formwork element (10) comprising data acquisition means
(16a, 16b, 16c, 16d, 16e) comprising at least one sensor unit (18a, 18b, 18c, 18d,
18e) configured to acquire data in relation to the stress exerted on the formwork
element (10) by the building material (M), a control unit (20a, 20b, 20c, 20d, 20e)
configured to control the at least one sensor unit (18a, 18b, 18c, 18d, 18e) and/or
to process the acquired data, and a transmission unit (22a, 22b, 22c, 22d, 22e) configured
to transmit the acquired data to a device (24) located outside the formwork element
(10), wherein the control unit (20a, 20b, 20c, 20d, 20e) and the transmission unit
(22a, 22b, 22c, 22d, 22e) are arranged within the support structure (14), and wherein
the at least one sensor unit (18a, 18b, 18c, 18d, 18e) is arranged at least partially
within the support structure (14) .
8. The formwork element of claim 7, wherein the at least one sensor unit (18a) extends
through an opening (34) formed in the support structure (14), the sensor unit (18a)
comprising a pressure transducer holding body (66), a pressure chamber (60), a pressure
transducer (67) arranged at least partially within the pressure transducer holding
body (66) and inserted at least partially into or being arranged adjacent to the pressure
chamber (60) at a first axial end portion of the pressure chamber (60) and a membrane
(63) covering an opening of the pressure chamber (60) at a second axial end portion
of the pressure chamber (60), wherein the pressure chamber (60) contains a hydraulic
fluid and is configured to contact the building material (M) and to perform continuous
measurement of lateral pressure (P) on the form face (12) of the formwork element
(10).
9. The formwork element of claim 8, wherein the pressure chamber (66) is axially adjustable
in position through an opening formed in a base plate (61) of the sensor unit (18a),
wherein the sensor unit (18a) comprises fixing means (61a) configured to lock and
unlock the pressure chamber (66) relative to the base plate (61).
10. The formwork element of claim 7, wherein the at least one sensor unit (18a, 18b, 18c,
18d, 18e) is formed by a deflection sensor (18b) configured to perform continuous
measurement of a deflection of the form face (12) of the formwork element (10).
11. The formwork element of claim 10, wherein the deflection sensor (18b) comprises a
push rod (38) extending through an opening (40) formed in the support structure (14)
adjacent to the form face (12) of the formwork element (10), the push rod (38) abutting
the form face (12), wherein the push rod (38) is pre-loaded against the form face
(12) by a first spring element (42) .
12. The formwork element of claim 11, wherein the deflection sensor (18b) further comprises
a magnet lever (44) connected to the push rod (38) at a first end portion (44a) of
the magnet lever (44), wherein the magnet lever (44) at its second end portion (44b)
comprises a first permanent magnet (46) and a second permanent magnet (48), wherein
a hall effect sensor (50) is arranged between the first permanent magnet (46) and
the second permanent magnet (48) of the magnet lever (44), wherein the magnet lever
(44) is adapted to move upon movement of the push rod (38), and wherein the hall effect
sensor (50) is configured to detect a movement of the magnet lever (44).
13. The formwork element of any one of claims 7 to 12, wherein the at least one sensor
unit (18a, 18b, 18c, 18d, 18e) is formed by a strain gauge (18c) configured to measure
a load (L) on a tie rod (52) arranged between the formwork element (10) and an adjacent
formwork element (11) using compression strain gauge load cells (54) integrated in
a tie rod assembly (56).
14. The formwork element of any one of claims 7 to 13, wherein the at least one sensor
unit (18a, 18b, 18c, 18d, 18e) is formed by a temperature sensor (18d) configured
to measure a temperature of the building material (M), wherein the temperature sensor
(18d) forms contact with the building material (M) or is integrated in the pressure
sensor unit (18a), and/or a sound sensor (18e) configured to detect formwork (2) movements
using an electrostatic capacitor-based microphone attached to the form face (12).
15. Method for transmitting data for predicting stress on a formwork element (10) during
and/or after pouring a building material (M), in particular concrete, into a space
enclosed by a formwork (2) including the formwork element (10), the formwork element
(10) comprising a form face (12) and a support structure (14) which is attached to
the form face (12) and supporting the form face (12), wherein the form face (12) is
separated from or integrated into the support structure (14), the method comprising
the steps of:
acquiring data (S1) in relation to the stress exerted on the formwork element (10)
by the building material (M) by means of at least one sensor unit (18a, 18b, 18c,
18d, 18e) of a data acquisition means (16a, 16b, 16c, 16d, 16e) ;
controlling (S2) the at least one sensor unit (18a, 18b, 18c, 18d, 18e) by means of
a control unit (20a, 20b, 20c, 20d, 20e) and/or processing the acquired data (S2'),
wherein the control unit (20a, 20b, 20c, 20d, 20e) and the transmission unit (22a,
22b, 22c, 22d, 22e) are arranged within the support structure (14), and the at least
one sensor unit (18a, 18b, 18c, 18d, 18e) is arranged at least partially within the
support structure (14); and
transmitting (S3) the acquired data to a device (24) located outside the formwork
element (10) by a transmission unit (22a, 22b, 22c, 22d, 22e).
16. Method for predicting stress on a formwork element (10) during and/or after pouring
a building material (M), in particular concrete, into a space enclosed by a formwork
(2) including the formwork element (10), the method comprising the method for transmitting
data for predicting stress on a formwork element (10) of claim 14, and further comprising:
receiving (S4) the acquired data by means of the device (24) .
17. Method of claim 15 or 16, further comprising the step of measuring the stress exerted
on the formwork (2) at various positions in the formwork (2) by means of a plurality
of sensor units (18a, 18b, 18c, 18d, 18e).
18. Method of claim 16 or 17, wherein the device (24) is configured to perform an analysis
of the stress on the formwork element (10) during and/or after pouring the building
material (M) using the data received from the data acquisition means (16a, 16b, 16c,
16d, 16e) and data of previous building material (M) pours monitored by the system.